When trying to install the Maya plugin (v 2.5.245) at this screen I get the windows spinning cursor and no progress when clicking on any button ("Register...", "Next", or "Cancel"). I also tried registering from this link from google, but I got a non-helpful "Sorry, your submission had an error."
Weirdly, when I end the installer from Task Manager, I see the plugin in Maya and it works for CPU rendering (but not CPU/GPU or just GPU, for those I just get a black image, but that is a separate issue).
Installation hang screen
Link error